The effectiveness of filter material for respiratory protection worn by wildland firefighters

Abstract

During a wildland fire event, firefighters often receive significant exposure to smoke consisting of particulate matter (PM) and gaseous emissions. Major respiratory and cardiovascular health concerns are related to inhalation of smoke and respiratory protection (RP), such as masks, are one of the most important pieces of personal protective equipment (PPE) that can be used to mitigate this exposure. One barrier to RP implementation is that the effectiveness of different PPE worn by firefighters is not well studied in the literature. In this study, six different filtering materials were tested against simulated wildland fire smoke produced by smoldering Douglas fir needles in a custom-made lab-scale apparatus. Both PM and gases were measured with and without the filter material and their effectiveness is reported in this study. As expected, cloth bandanas, currently the most worn RP material, provided little benefit in terms of both PM and gaseous emissions reduction, while all other filter materials provided significant benefits. N95, P95 and P100 filters were very effective at removing PM and somewhat effective at filtering some gaseous species, especially those with nuisance VOC capabilities, although this effect may not be sustained for longer durations.